mpv/ta
wm4 8fc2bc1422 ta: fix logging of unfreed child allocations
Broken since commit f6615f00ee. This traversed the data
structure incorrectly, and caused a stack overflow due to infinite
recursion.
2020-02-29 20:12:31 +01:00
..
README ta/README: fix typos 2014-10-13 18:56:42 +02:00
ta.c ta: fix logging of unfreed child allocations 2020-02-29 20:12:31 +01:00
ta.h ta: remove two pointless wrappers 2020-02-23 19:48:25 +01:00
ta_talloc.c Fix use of ISC license 2017-04-15 16:20:00 +02:00
ta_talloc.h ta: remove two pointless wrappers 2020-02-23 19:48:25 +01:00
ta_utils.c ta: change API; ta_set_parent() and ta_set_destructor() never fail 2020-02-23 17:45:05 +01:00

README

TA ("Tree Allocator") is a wrapper around malloc() and related functions,
adding features like automatically freeing sub-trees of memory allocations if
a parent allocation is freed.

Generally, the idea is that every TA allocation can have a parent (indicated
by the ta_parent argument in allocation function calls). If a parent is freed,
its child allocations are automatically freed as well. It is also allowed to
free a child before the parent, or to move a child to another parent with
ta_set_parent().

It also provides a bunch of convenience macros and debugging facilities.

The TA functions are documented in the implementation files (ta.c, ta_utils.c).

TA is intended to be useable as library independent from mpv. It doesn't
depend on anything mpv specific.

Note:
-----

mpv doesn't use the TA API yet for two reasons: first, the TA API is not
necessarily finalized yet. Second, it should be easily possible to revert
the commit adding TA, and changing all the code would not allow this.

Especially the naming schema for some TA functions is still somewhat
undecided. (The talloc naming is a bit verbose at times.)

For now, mpv goes through a talloc wrapper, which maps the talloc API to TA.
New code should still use talloc as well. At one point, all talloc calls
will be replaced with TA calls, and the talloc wrapper will be removed.

Documentation for the talloc API is here:

    http://talloc.samba.org/talloc/doc/html/modules.html

There are some minor differences with mpv's talloc bridge. mpv calls abort()
on allocation failures, and the talloc_set_destructor() signature is slightly
different. libtalloc also has a weird 256MB limit per allocation. The talloc
wrapper supports only a strict subset of libtalloc functionality used by mpv.